I bought a used 2009 Prius. Somehow it refuses to go into accessory mode. I press the power button without stepping on the brake pedal and nothing happens. Anyone have any ideas? I wonder if this symptom is related to the fact that this car is supposedly equipped with SKS (fob has silver logo and there is a black square on driver door outside handle) but the smart key functionality does not work? (The car came with only one key fob.)
How do you start the car normally? If the SKS is not working, then the Power button will ignore what ever you do until you plug a registered fob into the dash. I would strongly recommend getting another fob ASAP. If you loose the one, it will become a very big problem to get up and running again. For example, look for posts by PC member Ovni, who sells backup keys for the gen II.
Yes, the "key" button under the dash is turned on. I've tried both on and off positions just to make sure.
Changed the key fob battery? Checked the 12V battery? All strange electrical problems in the Prius should cause the 12V battery to be suspect until proven otherwise. Follow this test and report back all three numbers. Weird stuff happening? MPGs dropping? Test The Battery | PriusChat
Thanks for the suggestions. Yes, I changed the fob battery. Since I can't get the car into ACC mode, I couldn't check the battery voltage via the display without having it be in READY mode, which meant that when I look at the battery voltage display, it reads 14.1 V, i.e., it's getting charged. So I used a volt meter to measure the battery directly with the car turned off. At that point, the reading was 12.75 V. Then I opened the doors and turned on the headlights, which dropped the reading to 11.99 V. It seems the battery is not bad.
Sounds good but you might want to check it after sitting overnight. Mind you I'm no expert but I think next I would try disconnecting the 12V for a few minutes and reconnecting. If all the batteries check out good maybe the system needs rebooting? All other electrical systems work ok? No lights not burning, the sound and climate systems good, the inverter coolant is flowing in the container? It is strange.
Acc mode can be entered by Not stepping on the brake, touching the power button twice... Don't forget to get out of acc mode by pressing the power button once, don't underestimate the quickness in which the 12v will lose it's charge in acc mode
I rechecked the battery after sitting overnight, and it still checks out. I also disconnected the battery for several minutes and reconnected. No change. Still cannot get into ACC mode. Other electrical systems work O.K. Lights are bright, sound and climate systems good, etc. This might be a crazy idea, but I suspect (for various reasons) that this used to be a rental car. Could they have deliberately disabled some functionalities for whatever reason?
Wait...I think I found a thread that exactly matches this symptom: No ACC mode | PriusChat. I'll have to go check if there is any suspicious aftermarket wiring installed under the dash...
